Service performances of all materials are generally determined by developing structure-property relationships. For example, the service performance and properties of a material made by a phase transformation process generally depend on the resulting microstructure of the transformed material. Phase transformation processes can include laser cladding, laser alloying, laser welding, laser melt quenching as well as such processes carried out using non-laser sources of energy (e.g., electron-beam and other techniques for applying sufficiently high localized heat to carry out the desired phase transformation process). The materials with which the disclosed invention can be used are typically metal materials; that is, materials comprising a single, pure elemental metal, binary, tertiary, and other plural combinations of different elemental metals, as well as combinations of one or more metals with other non-metals. However, ceramics and other non-metal materials can also be formed by phase transformation into varying microstructures.
Presently, known methods for determining the microstructure of a material resulting from a phase transformation process are mostly a postmortem analysis where a materials scientist takes a solidified piece of the material and carries out a polishing-etching process to determine different phases by Optical and Scanning Electron Microscopes (SEM). Then, often a post processing is adapted to create the desired microstructure for desired properties. In-situ identification of phase formation during synthesis has the possibility of saving a significant amount of human time and capital resource for materials and industry. For researchers, it could provide material scientists with a repeatable process for the synthesizing materials with a desired microstructure.
US Patent Application Publication No. 2010/0133247 A1, entitled “Monitoring of a Welding Process,” includes additional information concerning the components and steps used for collecting, processing, and utilizing the light emitted from the plasma during phase transformation. The complete content of US Patent Application Publication No. 2010/0133247 A1 is hereby incorporated by reference.